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Indexed by:期刊论文

Date of Publication:2011-06-15

Journal:JOURNAL OF NUCLEAR MATERIALS

Included Journals:SCIE、EI

Volume:413

Issue:2

Page Number:90-94

ISSN No.:0022-3115

Abstract:The stability and migration behavior of helium and self defects in vanadium and V-4Cr-4Ti alloy are studied by first-principles calculations. The tetrahedral site is found as the most stable configuration for interstitial He, followed by the octahedral and substitutional sites. Among the self defects, the mono-vacancy has lower formation energy (1.71 eV for V and 2.14 eV for V-4Cr-4Ti alloy) than the self interstitial ones. The migration energies for He hopping between the tetrahedral sites are 0.06 and 0.09 eV for vanadium and V-4Cr-4Ti alloy, respectively. Our calculations reveal strong repulsion between two interstitial He atoms and strong attraction between He and vacancy, suggesting that vacancy acts as a trapping site for He impurity and a seed for further bubble formation. (C) 2011 Elsevier B.V. All rights reserved.